The client
A family building on $95,000 of owned land outside Lethbridge, Alberta, is approved for an insured self-build mortgage against a $310,000 construction contract. The build was on budget and on schedule until structural-materials pricing rose mid-project.
Land value
$95,000, owned outright
Lethbridge
Construction contract
$310,000
Original approved scope
Approved mortgage
$317,440
Insured, based on $405,000 as-complete value
The overrun
$22,000
From higher structural-materials pricing
Combined income
$8,100/month
Both salaried
The problem
A cost overrun mid-build has a well-worn playbook: inject cash, or borrow more against a re-underwritten, larger loan. This family wanted neither. A larger mortgage would have meant a fresh loan-to-value calculation on a file that was already approved and moving; a cash injection was money they preferred to keep in reserve.
Why the usual fixes weren't the only option
- ▸A bigger mortgage means re-underwriting the whole file against a new as-complete value -- not a small administrative step
- ▸A cash top-up solves the immediate gap but permanently reduces the family's own reserve
- ▸The one lever nobody had priced yet: spending less on the SAME finished house, rather than finding more money to spend the same amount
The house being built didn't need to change size or scope -- only which specific products went into finishing it.
The numbers
The approved $317,440 mortgage was priced against a $405,000 as-complete value from the start; the goal was to protect that number exactly, not to recalculate it, even against a backdrop of rising residential construction costs across Canada.
| Absorbing the overrun inside the existing budget | Amount |
|---|---|
| Approved insured mortgage | $317,440 |
| Mid-build cost overrun | $22,000 |
| Flooring downgrade (hardwood to laminate) | -$9,000 |
| Countertop downgrade (quartz to laminate) | -$6,000 |
| HVAC downgrade (upgraded to standard) | -$7,000 |
| Total finishes downgraded | $22,000 |
| Ratio check at the qualifying rate | Figure |
|---|---|
| Minimum qualifying rate on a 4.90% contract rate | 6.90% |
| Payment at the qualifying rate, 25 years | $2,204 |
| GDS (payment + $290 tax + $125 heat) ÷ $8,100 income | 32.3% |
| TDS (GDS numerator + $300 car loan) ÷ $8,100 income | 36.0% |
32.3% GDS and 36.0% TDS never moved from what the file was originally approved on -- the mortgage amount, the premium band and the ratios are all exactly what they were before the overrun surfaced.
The solution
A mortgage associate licensed under Alberta's Real Estate Act, regulated by RECA, treated the overrun as a scope-and-price conversation with the builder before treating it as a financing problem at all.
First, confirmed the overrun's exact size and cause with the builder. A documented $22,000 increase in structural-materials pricing, not a scope change the family had asked for.
Second, asked the builder to price a specific downgrade list rather than default to a change order for more money. Laminate flooring instead of hardwood, laminate instead of quartz counters, and the standard HVAC package instead of the upgraded one, each individually quoted.
Third, matched the downgrade list's total savings to the overrun exactly, and confirmed with the lender that the approved mortgage amount required no change. A useful comparison for framing the trade-off is worked through in GDS and TDS, worked.
The outcome
The build finished on the original $317,440 mortgage, never re-underwritten, with GDS at 32.3% and TDS at 36.0%, exactly as first approved.
Alberta has no verified land transfer tax fact on file for a dollar figure; this build did not involve a land purchase at the mortgage stage in any case, since the lot was already owned outright.
What to take from this file
- 01A cost overrun doesn't always need more money. Spending less on the same finished house is a real, usable alternative to a cash top-up or a bigger loan.
- 02Ask the builder for a specific, itemized downgrade list before defaulting to a change order. Individually priced substitutions are easier to match to an exact overrun than a lump-sum renegotiation.
- 03Protecting the originally approved mortgage amount avoids a fresh loan-to-value calculation entirely. A bigger loan means re-underwriting; a smaller finish budget doesn't.
- 04Match the downgrade total to the overrun deliberately, not approximately. A precise match is what let this file skip re-underwriting altogether.
- 05Every builder prices its own substitutions differently. There is no published schedule for what a specific finish swap saves -- it has to be quoted case by case.
Sources
Every regulatory figure in this file traces to one of these primary sources. Client details and anything that varies by lender are illustrative, as flagged below.
- ▸CMHC — Purchase (Mortgage Loan Insurance) — default-insurance premium schedule by LTV band (25-year amortization).
- ▸CMHC — CMHC Home Start — minimum down payment tiers (5%/10%) and the $1.5M insured price cap.
- ▸OSFI — Minimum qualifying rate for uninsured mortgages — the minimum qualifying rate — greater of contract rate + 2% or 5.25%.
- ▸CMHC — CMHC Reviews Underwriting Criteria — GDS 39% / TDS 44% maximums and the 600 credit-score floor for insured files.
- ▸Provincial/territorial mortgage-broker legislation fetched directly (bclaws.gov.bc.ca, legisquebec.gouv.qc.ca, fcaa.gov.sk.ca, web2.gov.mb.ca, nslegislature.ca, assembly.nl.ca) plus FCNB's own site for NB and CanLII's index for PE — see notes for per-province method — provincial mortgage regulators and licence titles.
Illustrative in this file — lender-specific, not rules:
- ▸4.90% contract rate — rates move daily; not a quote.
- ▸the specific downgrade list and its dollar savings — each builder prices its own finish substitutions; there is no published schedule for what any specific swap saves.
Authority & provenance
How this case file was built
We publish the origin, the verification method and the reviewer for every case file, so you can judge how far to trust it before you rely on it with a client.
Where it comes from
Derived from files handled by Treadstone’s fulfillment desk and from scenarios contributed by partner brokerages. Names, employers, exact amounts and dates are changed so no client or file is identifiable.
Provenance: Composite — a pattern seen repeatedly on fulfilled files, not a single transaction.
What is verified
Every regulatory figure traces to a primary source listed above and was checked against it on the date shown. The arithmetic is recomputed by machine on every rebuild.
Anything that varies by lender is labelled illustrative rather than stated as a rule.
Who reviewed it
Reviewed for Canadian regulatory accuracy before publication, and re-checked whenever a cited rule changes.
Reviewed by: Nicholas Parson, Treadstone Associates — reviews every case file before publication.
This case file is professional reference material for licensed mortgage professionals. It is not advice to a borrower, and it is not a lender commitment. Insurer rules, qualifying rates and provincial taxes change — confirm the current position with the insurer, regulator or lender before you rely on any figure here in a live file.